97 research outputs found

    QUAliFiER: An automated pipeline for quality assessment of gated flow cytometry data

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    Effect of Concept Cartoons on Kindergarten Pupils’ Numeracy and Science Performance in Sagnarigu-Tamale, Ghana

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    This study sought to establish the effect of Concept Cartoons on Kindergarten Pupils’ Numeracy and Science Performance at a demonstration primary school in Sagnarigu-Tamale, Ghana using the experimental research design. The population of the study was 100 KG-2 A and B Pupils in the school. A purposive sampling technique was used to select an intact class of 58 pupils that had difficulty in participation and performance in natural science and numeracy. A pre-test was conducted to determine the initial performance of pupils before the intervention that was done through teaching with the support of the concept cartoons. The analysis of the first two objectives involved mean scores and standard deviation. Pre-test and post-test scores were analysed to address the two objectives. The study established that the use of concept cartoons significantly improved the pupils’ achievement in natural science and numeracy lessons. Therefore, the use of concept cartoons as a teaching aid is a powerful approach to improve the performance of pupils in sciences and numeracy. The study recommended that teachers of sciences and numeracy in early primary education ought to use the concept cartoon approach in order to improve the performance of pupils in the s

    Variable-focus microscopy and UV surface dissolution imaging as complementary techniques in intrinsic dissolution rate determination

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    This work reports a novel approach to the assessment of the surface properties of compacts used in Surface Dissolution Imaging (SDI). SDI is useful for determining intrinsic dissolution rate (IDR), an important parameter in early stage drug development. Surface topography, post-compaction and post-SDI run, have been measured using a non-contact, optical, three-dimensional microscope based on focus variation, the Alicona Infinite Focus Microscope, with the aim of correlating the IDRs to the surface properties. Ibuprofen (IBU) was used as a model poorly-soluble drug. DSC and XRD were used to monitor possible polymorphic changes that may have occurred post-compaction and post-SDI run. IBUs IDR decreased from 0.033 mg/min/cm2 to 0.022 mg/min/cm2 from 10 to 20 min, respectively, during the experiment. XRD and DSC showed no form changes during the SDI run. The surface topography images showed that a distinct imprint was embossed on the surfaces of some compacts which could affect IDRs. Surface parameter values were associated with the SDI experiments which showed strong correlations with the IDR values. The variable-focus microscope can be used as a complimentary tool in the determination of IDR values from the SDI

    Differential gene expression profiles are dependent upon method of peripheral blood collection and RNA isolation

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    <p>Abstract</p> <p>Background</p> <p>RNA isolation and purification steps greatly influence the results of gene expression profiling. There are two commercially available products for whole blood RNA collection, PAXgene™ and Tempus™ blood collection tubes, and each comes with their own RNA purification method. In both systems the blood is immediately lysed when collected into the tube and RNA stabilized using proprietary reagents. Both systems enable minimal blood handling procedures thus minimizing the risk of inducing changes in gene expression through blood handling or processing. Because the RNA purification steps could influence the total RNA pool, we examined the impact of RNA isolation, using the PAXgene™ or Tempus™ method, on gene expression profiles.</p> <p>Results</p> <p>Using microarrays as readout of RNA from stimulated whole blood we found a common set of expressed transcripts in RNA samples from either PAXgene™ or Tempus™. However, we also found several to be uniquely expressed depending on the type of collection tube, suggesting that RNA purification methods impact results of differential gene expression profiling. Specifically, transcripts for several known PHA-inducible genes, including IFNγ, IL13, IL2, IL3, and IL4 were found to be upregulated in stimulated vs. control samples when RNA was isolated using the ABI Tempus™ method, but not using the PAXgene™ method (p < 0.01, FDR corrected). Sequenom Quantiative Gene Expression (QGE) (SanDiego, CA) measures confirmed IL2, IL4 and IFNγ up-regulation in Tempus™ purified RNA from PHA stimulated cells while only IL2 was up-regulated using PAXgene™ purified (p < 0.05).</p> <p>Conclusion</p> <p>Here, we demonstrate that peripheral blood RNA isolation methods can critically impact differential expression results, particularly in the clinical setting where fold-change differences are typically small and there is inherent variability within biological cohorts. A modified method based upon the Tempus™ system was found to provide high yield, good post-hybridization array quality, low variability in expression measures and was shown to produce differential expression results consistent with the predicted immunologic effects of PHA stimulation.</p

    An investigation into the use of low quantities of functional additives to control drug release from hot melt extruded solid dispersions for poorly soluble drug delivery

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    The motivation of this study is to demonstrate the practicality of producing slow release and fast release products in a single-step hot melt extrusion (HME) process. HPMCAS as the carrier material showed good potential in monolithic controlled release formulations for the model drug, carbamazepine (CBZ). As binary formulations, CBZ-HPMCAS extrudates showed zero-order release over 24 hours which was accompanied by the swelling of the extrudates. A range of functional excipients was used at low quantities to modulate the release rate. The release rates of the HME extrudates could be either accelerated by the incorporations of low quantities (5% w/w) of soluble additives or further sustained by adding lipid excipient, Gelucire 50/13. Clear phase separations of the soluble additives including crosscarmellose sodium, sodium starch glycolate, maltodextrin and lactose in the extrudates led to higher interior porosity and quicker erosion in comparison to the binary extrudates. The phase separated Gelucire in the extrudates led to the substantial swelling of the extrudates and resulted in further prolonged drug release. This study provided clear formulation strategies for modulating the drug release rate from controlled release formulation prepared directly by single-step HME. In addition, this research work also evaluates for the first time HME extrudates simultaneous swelling and drug release using this UV imaging technique. The whole dose cell of this instrumentation is utilised to provide insights into the dissolution process of solid dispersions prepared by HME

    Hot-melt extrusion process impact on polymer choice of glyburide solid dispersions : the effect of wettability and dissolution

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    The aim of this study was to evaluate the choice of polymer and polymer level on the performance of the microstructure and wettability of hot-melt extruded solid dispersion of Glyburide (Gly) as a model drug. The produced solid dispersion were characterised using scanning electron microscopy (SEM), image analysis using a focus variation instrument (FVI), differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), X-ray microtomography (XÂľT), dynamic contact angle measurement and dissolution analysis using biorelevant dissolution media (FASSIF). SEM and focus variation analysis showed that the microstructure and surface morphology was significantly different between samples produced. This was confirmed by further analysis using XÂľT which showed that an increase in polymer content brought about a decrease in the porosity of the hot-melt extruded dispersions. DSC suggested complete amorphorisation of Gly whereas XRPD suggested incomplete amorphorisation. The static and dynamic contact angle measurement correlated with the dissolution studies using FASSIF media indicating that the initial liquid imbibition process as captured by the dynamic contact angle directly affects the dissolution performance

    Development of a novel method utilising dissolution imaging for the measurement of swelling behaviour in hydrophilic matrices

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    A variety of imaging techniques are currently used within the field of pharmaceutics to help understand and determine a wide range of phenomena associated with drug release from hydrophilic matrix tablets. This work for the first time aims at developing an appropriate testing imaging methodology using a surface dissolution imaging instrument (SDI2) for determining the swelling of whole compacts using hypromellose as a model hydrophilic matrix former. The influence of particle morphology (CR and DC grades) and two compressional forces (5 and 15 kN) on the initial swelling behaviour of hypromellose were investigated. The results showed that a lower absorbance of 50 mAu with a wider measurement zone proved successful in determining the edge of the gel layer and growth measurements in real-time with high level of details under flow. Despite the differences in the morphology of the grades of hypromellose tested, it was however discovered that gel growth was statistically similar between them which may be attributed to their similar chemistry. This novel method also highlighted differences in the hydrated polymer’s appearance which may have been as a result of differences in porosity and solid fraction. This information is of great importance to a formulator as gel growth plays a crucial role in determining drug release from polymer compacts
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